The present invention relates to a wheeled chair for use in a hospital or other health care facility, and particularly to an ambulatory care chair that converts between a chair and a table. More particularly, the present invention relates to a wheeled hospital chair having articulated patient-support sections that move relative to one another between a generally upright position and a generally horizontal table position and that can be tilted and elevated so that a patient can rest and be transported in the chair. The chair can be converted to a table for supporting the patient during medical procedures without having to transfer the patient between separate chairs and tables. The extension and retraction of the leg section of the chair and the hi-lo adjustment of the chair are accomplished using the same actuator for actuating drive mechanisms.
Carriers for transporting a patient in a hospital or other care facility from one location to another are well known in the art. Conventional wheelchairs may be used by a caregiver to transport the patient when the patient is conscious and capable of sitting in an upright position. Such wheelchairs may also be used in a hospital to transport patients between hospital stations for medical testing, therapy, or recreation. In addition, wheelchairs having features designed to aid in the transfer of a patient between the hospital bed and the wheelchair are known in the art. See, for example, U.S. Pat. No. 4,453,732 to Assanah et al. and U.S. Pat. No. 4,119,342 to Jones. Each of these references discloses a wheelchair having back, seat, and leg sections that are convertible to a horizontal stretcher configuration.
Conventional stretchers having flat patientsupport surfaces may also be used as a carrier to transport patients. For example, conventional stretchers may transport the patient before or after surgery is performed on the patient or when the patient is otherwise incapacitated or unable to sit upright. Conventional stretchers that raise and lower can be used to transfer patients from the stretcher to a surface of an operating table, a bed, or another patient surface by adjusting the height of the stretcher to the same height as the patient surface receiving the patient. See, for example, U.S. Pat. No. 4,629,242 to Schrager and U.S. Pat. No. 3,304,116 to Stryker, each of which discloses a stretcher having a patient-support surface that can be vertically adjusted.
Caregivers may wish to adjust the position of the patient supported by the carrier. In addition, a patient supported by the carrier may wish to adjust their own position for reasons of comfort. Carriers having articulated back, seat, and leg sections that assist patients in moving between a lying-down position and a sitting-up position are known in the art. See, for example, U.S. Pat. No. 5,230,113 to Foster et al.; U.S. Pat. No. 5,398,357 to Foster; and U.S. Pat. No. 4,862,529 to Peck, all of which are assigned to the assignee of the present invention. Each of these references discloses a hospital bed that is convertible to a chair configuration.
Some hospital beds having patient-support decks including articulated patient-support sections also have mechanisms that adjust the height of the patientsupport deck relative to a base frame. In addition, these hospital beds may include mechanisms that tilt the patient-support deck relative to the base frame. See, for example, U.S. Pat. No. 5,148,562 to Borders et al.; U.S. Pat. No. 4,894,876 to Fenwick; and U.S. Pat. No. 4,862,529 to Peck, all of which are assigned to the assignee of the present invention. Each of these references discloses a bed having an intermediate frame that is mounted to a base frame for vertical and tilting movement with respect thereto. Each reference also discloses an articulated patient-support deck carried by the intermediate frame and including patient-support sections that are movable relative to the intermediate frame.
What is desired is an ambulatory care chair that can be used both to transport the patient and as an operating chair or table when minor surgical procedures are to be performed on the patient. The ambulatory care chair should provide a comfortable and adjustable patient-support surface on which the patient can rest prior to such procedures, when recovering after such procedures, and at other times when desired. Such a chair should have articulated back, seat, and leg sections that are adjustable between a sitting-up position supporting the patient in a sitting position and a table position having the back, seat, and leg sections aligned and defining a generally planar upwardly-facing patient-support surface supporting the patient in a supine position. In addition, the ambulatory care chair should include mechanisms for raising and lowering the back, seat, and leg sections relative to a floor and mechanisms for tilting the back, seat, and leg sections.
According to the present invention, a chair is provided for supporting a patient above a floor. The chair includes a base frame and an intermediate frame coupled to the base frame for pivoting movement relative to the base frame about a generally horizontal transverse axis. An articulated patient support is mounted to the intermediate frame. The patient support has longitudinally spaced back and seat sections mounted to the intermediate frame for movement relative to one another and relative to the intermediate frame. The back and seat sections are movable relative to the base frame about the horizontal transverse axis of the intermediate frame.
In preferred embodiments, the ambulatory care chair includes an articulated patient support defining a patient-support surface. The patient support has back, seat, and leg sections that are mounted to the intermediate frame for movement between a sitting-up position carrying the patient in a sitting position and a table position carrying the patient in a supine position. The back, seat, and leg sections are lockable relative to the intermediate frame in an infinite number of positions between the sitting-up and table positions. In addition, the patient support can be tilted between a Trendelenburg position and a reverse Trendelenburg position when the sections of the patient support are in the table position. When the sections of the patient support are in the sitting-up position, the patient support can be tilted rearwardly to rock the patient to a leaned-back position or forwardly to assist with patient egress from the chair.
The ambulatory care chair includes a base frame including a staging frame mounted for vertical movement relative to a lower frame and an intermediate frame coupled to the base frame for pivoting movement relative to the base frame about a generally horizontal transverse axis. An articulated patient support including longitudinally spaced back, seat, and leg sections is mounted to the intermediate frame. The patient support is mounted to the intermediate frame for movement relative to one another and relative to the intermediate frame. The back, seat and leg sections are movable relative to the base frame about the horizontal transverse axis. The chair includes a hydraulic system having a first hydraulic cylinder actuating vertical movement of the staging frame relative to the lower frame, a second hydraulic cylinder actuating movement of the leg section relative to the seat section, and a pump actuating both the first and second hydraulic cylinders.
The ambulatory care chair also includes foot pedals that control upward and downward movement of the staging frame, the intermediate frame, and the articulated patient support relative to the lower frame. A recline release handle unlocks the back, seat, and leg sections of the patient support for movement between the sitting-up and table positions relative to the intermediate frame. In addition, a tilt handle can be provided for unlocking the intermediate frame from the staging frame of the base frame for forward and rearward tilting movement about the horizontal axis relative to the staging frame.
The ambulatory care chair also includes a push bar having a grip extending across the back of the chair. When the patient support is in the sitting-up position, the caregiver can grasp the push bar when transporting a patient on the chair. A deployable center wheel can be easily deployed against the floor by the caregiver to assist with steering the ambulatory care chair. The caregiver can move the center wheel into and out of engagement with the floor by actuating a foot pedal coupled to the center wheel by a center wheel deployment mechanism. The foot pedal is also coupled to a braking mechanism which brakes and releases casters mounted to the lower frame. The center wheel automatically deploys against the floor or retracts away from the floor when the caregiver operates the braking mechanism.
When the foot pedal is in a braking position, the braking mechanism brakes two of the casters and prevents the braked casters from rotating or swivelling relative to the base frame. In addition, the center wheel engages the floor providing a third braking point to prevent inadvertent rotation of the chair about the braked casters. When the foot pedal is in a neutral position, the casters are free to rotate and swivel and the center wheel is spaced apart from the floor. When the caregiver moves the foot pedal to a steering position, the casters are free to rotate and swivel and the center wheel is in contact with the floor to assist in steering the chair by providing a frictional contact area about which the chair can be easily turned.
The ambulatory care chair can also include a pair of arm rest assemblies having generally upwardly-facing arm-support surfaces that can be infinitely positioned relative to the seat section between a raised position and a lowered position. Each arm rest assembly includes a locking mechanism that can be locked to lock the arm-support surface at any position between the raised and lowered positions and that can be released allowing the arm-support surface of the arm rest assembly to move relative to the seat section. Each arm rest assembly includes a release handle for releasing the locking mechanism to unlock the arm-support surfaces for upward and downward movement relative to the seat section.
It is within the scope of the invention as presently perceived to mount each arm rest assembly to a side portion of the seat section so that the arm-support surfaces move with the seat section. It is also within the scope of the invention as presently perceived to mount each arm rest assembly to the intermediate frame adjacent to side portions of the seat section so that the arm rest assemblies move with the intermediate frame.
In the upward raised position, the arm-support surfaces of the arm rest assemblies can carry the arms of a patient sitting-up on the patient-support surface when the patient support is in the sitting-up position. In the lowered position, the arm-support surfaces are out of the way of the patient-support surface both to provide a caregiver with unobstructed access to the patient carried by the chair and so that the patient can be transferred between the patient-support surface and another patientsupport device without interference from the arm rest assemblies.